Questions tagged [performance]
is for Emacs performance-related issues. Use additional tags to indicate which aspects of Emacs the performance issue is about: startup, navigation, search, screen updates, compilation, execution, debugging, and so on.
98
questions
1
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1
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27
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textual edits of R script drives up R process cpu load (ESS)
I'm using ESS (emacs speaks statistics) to edit R code. Once the R process is running, every textual edit in the buffer imposes substantial computational demand onto the R process (which I see top in ...
- 23
1
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1
answer
31
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Profiler/Benchmark Macro Like the `Time` in Common Lisp
To profile Elisp code, I tried benchmark.el and some profiler--prefixed built-in functions.
But all their reports are either non-human-readable or inadequate.
I think the ideal outcome is like what ...
- 2,484
0
votes
1
answer
24
views
Ignore tags during traversal in org-mode sparse tree match (performance)
I have a huge org file and I use the sparse tree function a lot to help me plan my weeks/months. (The agenda mode just doesn't do it for me; I really need to see it in the context of the tree.)
...
- 400
0
votes
2
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121
views
Reducing Emacs Startup Time
I read that changing the default garbage collector settings is not recommended https://lists.gnu.org/archive/html/help-gnu-emacs/2007-06/msg00243.html however I noticed it can make an impact on the ...
- 307
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0
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27
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When opening a file with prettier-mode it seems to take a very long time
I've recently started using prettier to format a legacy React project I've taken over.
So I've fired up prettier in my init.el:
(use-package prettier-js
:straight t
:hook ((js-mode . 'prettier-js-...
- 175
1
vote
1
answer
34
views
Timing a while loop
I am running two embedded loops that might take a long time. Would like to time the inner while loop. What can I do?
- 89
3
votes
1
answer
91
views
Company Reftex slow when searching for labels
I am writing on a large LaTeX Document using Emacs with AUCTeX, RefTeX and Company for autocompletion. RefTeX for citations is working fine and finds my bibliography entries really fast. However, when ...
- 41
2
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1
answer
88
views
Why is navigating in large `*shell*` buffer so slow?
For convenience (at least so far) I am running my program that produces a lot of debug output in Emacs shell.
However I have a problem:
Sometimes (not all the time) moving the cursor (up, down, left, ...
- 173
1
vote
1
answer
198
views
Slow start-up in MS Windows and relation to the Windows registry
I am using Doom in MS Windows with Emacs 27.2. I am experiencing some very slow start-up times (I included the output of benchmark-init/show-duration-tree at the end).
Also, the first actions I ...
- 51
0
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0
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126
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Debugging Issue: After Updating Emacs Input Lags Massively
After updating Emacs, I am seeing incredibly lagging input performance. I thought the slowness was due to LSP, but it seems to persist even when I disable LSP-mode. Unless I disable all major and ...
- 101
1
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0
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189
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Scrolling through rust-lsp suggestions is very slow. How to go about debugging this?
I'm trying to set up Emacs with rust-lsp ( following this guide). The suggestions from the rust-analyzer are being picked up as you can see in the screenshot.
But when I attempt to scroll through them ...
- 113
0
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0
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72
views
What is causing slowness when pasting text to terminal emacs (emacs -nw)?
For work, I run terminal emacs inside tmux on a remote server, which I access via PuTTY on a Windows machine. (So far, I haven't found a better way to pickup where I left off when editing remote code.)...
- 1
0
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1
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539
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Emacs / Doom emacs taking a lot of memory
I'm using Doom Emacs, which is taking a lot of Memory if my browser is opened with 10 tabs.
What can I do to reduce amount of memory being used, without sacrificing the packages?
My config.el is as
(...
1
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0
answers
130
views
Really slow editing long org-mode blocks
When editing inside a long org-mode block (#+BEGIN_.... - #+END_....) Emacs is really slow (it can take several seconds to write a single character), while editing the rest of the buffer takes normal ...
- 251
2
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1
answer
616
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Emacs is slow, intermittently hangs, freezes when I "come back to it", profiler says `savehist`
When I use Emacs it seems fine mostly, but since recently every couple of minutes it becomes extremely slow for a while. When I change focus to another app, and come back after a while, it is ...
- 183
4
votes
1
answer
664
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Is there any way to get the memory size (usage) of a Lisp variable/value?
Basically sizeof for lists, hashmaps, etc., with nested structures.
I could of course disable garbage collection and then compare numbers from memory usage functions before and after allocation, ...
- 394
0
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1
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200
views
Can't disable font-lock-mode
If I have font-lock on and I do M-x find-library RET simple RET, I have colours:
If I then M-x font-lock-mode to disable the mode, the colours disappear in the currently-visible portion of the buffer:...
- 738
5
votes
1
answer
81
views
Is there an efficient way to tell which parts of my startup of Emacs take the longest to load?
I have been trying to make the start-up times better. Almost all of my init.el is broken into use-package declarations like this:
(use-package x ...)
(use-package y ...)
(use-package z ...)
I want to ...
- 896
2
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0
answers
71
views
Package autoloading and use-package
I'm a beginner on emacs and I don't understand packages autoloading and use-package.
I see a lot of configs online which use 'use-package' and recommends installing packages with package manager (...
- 21
1
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0
answers
268
views
How can one debug a situation when emacs is unresponsive on Windows?
There is an operation in my setup which makes emacs unresponsive with high CPU.
I checked the emacs process with process monitor, but it does not wait for an other process, so I guess it must be ...
- 1,158
1
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1
answer
567
views
What is causing Emacs remote shell to be slow on completion?
So basically I am doing the following:
Opening a dired buffer with tramp on a remote.
Opening a shell on the remote (M-x shell)
Then if I try for example to type any command such as ls -la the ...
1
vote
1
answer
287
views
Slow markdown-mode as Emacs spends lots of time fontifying
Emacs on my Mac got upgraded when I upgraded some other package in Homebrew and now working with Markdown files is very slow. I'm now running the railwaycat/emacsmacport/emacs-mac package version with ...
- 301
1
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0
answers
379
views
EWW very slow opening of certain pages
This question was asked on stackoverflow. Just cross posting it here for better visibility. I am too facing the same issue.
I'm using EWW Emacs browser for opening various remote pages(mostly ...
- 93
2
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0
answers
42
views
Is (forward-char N)'s runtime complexity O(N)?
Internally, the text of a buffer is stored as a char array. The encoding used is based on UTF-8, which may use a variable number of bytes to represent different code points. Does the variable-length ...
- 153
4
votes
3
answers
2k
views
Improve emacs performance when working on large files
I'm a former vim user that switched to emacs + evil with a still relatively simple configuration with only 36 packages. I'm really happy with the additional functionality emacs delivers, but one thing ...
- 41
0
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0
answers
395
views
Windows File open SLOW
Windows 10
Emacs 27.1
From C-x C-f File
Till seeing the file actually open can take almost a minute!
Tried emacs instead of runemacs.
Also Menu-file-visit
All the same
I think there's some Mcafee ...
- 329
1
vote
1
answer
54
views
How to improve ‘jedi‘ package's load time
When I try to use jedi package I get following message in the minibuffer.
This feature requires the ‘jedi‘ package to be installed. Please check ‘elpy-config‘ for more information.
Elpy Configuration
...
- 1,164
3
votes
1
answer
78
views
What is the runtime complexity of using beginning-of-line?
I did a test where going to from the end to the beginning of a 50 million length line happens instantly when using beginning-of-line. I wonder if this is because it is a C primitive or because Emacs ...
- 153
1
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1
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260
views
How to diagnose emacs running at 100% cpu
I'm having a problem where occassionally emacs will run at 100% cpu, and just hang forever.
I've attached gdb to the process, and this is the stacktrace:
#0 0x00007fc210e5c5bb in pthread_sigmask () ...
- 545
1
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1
answer
127
views
How to measure the performance of the mode-line?
Currently when making changes to the mode-line, I try to write efficient elisp,
However I don't know for sure if what I'm doing is in fact efficient.
How could I test the mode-line performance?
For ...
- 8,209
0
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0
answers
80
views
emacsclient spending a lot of time resetting faces
When I launch emacsclient or make a new frame it spends ~2s in:
- make-frame 312 42%
- frame-creation-function ...
2
votes
2
answers
3k
views
Long Emacs start-up time (20~60s) on Windows 10
I have a working setup of emacs on Windows 10 that I like so far. However, I find that emacs start-up takes very long. It can be anywhere from 20s to 60s. I tried installing the benchmark-init package ...
- 133
0
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1
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224
views
How to throttle or debounce an elisp method?
I have a very file system intensive function that's being called many times a second. Wish to slow things down a little, anyone knows a way to throttle that function call in elisp?
[EDIT - 04/12/20]:
...
- 113
1
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0
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174
views
Poor performance with Tabbar
Tabbar is refreshing groups like 14+ times at once (probably number of tabs) and causing severe slowness with the mods I made on it (lots of IO to sort tabs in mod time). What is the preferred way to ...
- 113
0
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1
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164
views
Throttle transient-mark-mode highlighting?
When I'm using remote X forwarding to run X toolkit emacs and I press C-SPC and move the cursor around, things get very slow. The emacs profiler says all the time is spent in line-move-visual, but I ...
- 2,051
1
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1
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722
views
Why is emacs so bad at rendering long strings of text and what can be done to make it good?
Whenever a long string is to be rendered in an emacs buffer, which usually happens in the shell, emacs hangs and freezes, or takes too long to render the text compared to the terminal. What can be ...
- 237
1
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0
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433
views
Debugging slow find-file performance
Trying to figure out why find-file (C-x C-f) operations are taking a long time on Windows 10 with emacs 26.3. I tried to do profiling and got following results.
- command-execute ...
- 111
2
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1
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74
views
Troubleshooting a hanging `list-processes`
Normally I'd use M-x list-processes to see what Emacs is running in the background. But in this case list-processes itself hangs. What is the right thing to do in this situation?
- 5,928
5
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2
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155
views
How to pipe large files through fold before opening?
On a regular basis I need to open files that have really long lines, which unfortunately causes emacs to grind to a halt. My understanding is that this is a long-term issue with the renderer. I've ...
- 2,051
1
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0
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74
views
Performantly filter against a custom time-like property
My agenda view processes many items with SCHEDULED and DEADLINE fields, and fully generates from scratch in about 0.3s. However, if I append CUSTOM_SCHEDULED<"<now>" to my agenda view ...
- 5,928
1
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1
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248
views
Installation of Org-ref slows down start-up
I am super new to Emacs. I just followed the installation section of org-ref. I managed to get a simple citation working by adding bibliographystyle:plain to the file. This is one of the solution one ...
- 113
1
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0
answers
52
views
How are unrelated modes enabled?
I've been an emacs user for about a year now and I use it for Haskell programming. I chose to go the vanilla emacs route and customized a plain init file as I went along.
Over time, however, I ...
- 121
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0
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652
views
Remove scrollbar, faster
I like a clean interface. One without the clutter of scroll bars, or menu bars. So, to remove them, I have the following in my init.el
(progn
(menu-bar-mode -1)
(scroll-bar-mode -1)
(tooltip-...
- 111
7
votes
1
answer
2k
views
Find cause of cpu-usage?
Is there some way to find out, what in Emacs is causing spurious cpu usage?
Since a few days I notice Emacs retaining high CPU usage despite not being used actively, having no subprocesses, and not ...
- 1,541
2
votes
1
answer
151
views
Fastest way to draw pixels in Emacs
I'm currently working on a CHIP-8 emulator. This platform requires me to draw 64x32 black/white pixels, ideally at a speed between 30 and 60 frames per second. There's an extension to it that ...
- 21.7k
4
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0
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1k
views
byte-compile much slower in X (vs. -nw)
Setup
Windows 10 host with X server (VcXsrv)
Linux guest (Arch) in virtual machine (VMware)
Benchmark
(defmacro measure-time (&rest body)
"Measure the time it takes to evaluate BODY."
`(let ...
- 1,009
1
vote
2
answers
81
views
When local variables are "calculated"?
Does elisp calculate values of local variables at declaration or when calling them?
Say i want to find out what headlines in buffer are lvl2, and do stuff to them:
(defun map-org-heads ()
(org-...
1
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0
answers
170
views
C++-mode indenting performance depends on length of previous function?
Using c++-mode in emacs23.
UPDATE: In response to some early comments, I tested on emacs24 and emacs25, and see exactly the same behavior. I don't have convenient access to emacs26 or emacs27 (25 ...
- 111
2
votes
1
answer
68
views
Is it possible to disable magit calling :git branch --remote --contains <foo> when doing an interactive re-base?
I'm running on fairly large repository (Gentoo's portage, 2.5G .git) and slightly slow hardware (1Ghz arm64) and interactive re-basing is very slow. It seems the main culprit is "git branch --remote --...
- 4,616
0
votes
1
answer
108
views
Profile performance for a given command
Say I create a quick keyboard macro, but find that executing it in quick succession is extremely slow. How can I determine in what functions or packages this command is spending most of its time? ...
- 462